FIG. 5 shows a prior art example of this kind of keytops.
In the figure, reference numeral 1 represents a keytop as a whole. A display portion 2 having a predetermined shape, which faces on the top surface of the keytop 1, can be illuminated. This keytop 1 consists of base material 3 made of a transparent synthetic resin such as acrylic resin, etc., a base layer 4 made of colored paint such as white paint, etc., which is also transparent, applied on the surface of the base material 3, and a light intercepting layer 5 made of opaque paint such as black paint, etc., applied on the surface of the base layer 4. The display portion stated above is formed by removing a part of the light intercepting layer 5 having a predetermined shape by laser trimming so as to expose the base layer 4. In the light in the daytime, etc. the display portion 2 can be recognized by the eye, because the difference in the color between the base layer 4 and the light intercepting layer 5 is clarified by external light and on the other hand in the dark in the night or in a tunnel, etc. the display portion 2 illuminated in the dark can be recognized by lighting a lamp 6 disposed within the keytop 1 and by utilizing the fact that light emitted by it passes through the base material 3 and the base layer 4 and on the contrary it is not transmitted by the light intercepting layer 5.
Further a transparent hard coat layer may be applied over the whole external surface of the keytop 1 at need.
However, in the prior art keytop constructed as described above, since the directivity of the light emitted from the display portion 2 to the exterior is not so high, when it is illuminated in the night etc., a part of the light emitted from the display portion 2 is reflected towards the front glass, etc. Therefore so-called window reflection was apt to be produced. Consequently, in order to cut-off the light directed in undesired directions, measures have been taken by disposing the keytop 1 in a sequestered position such as in a recess. However, by this method, the restriction on the design of various members in the neighborhood of the keytop 1 is great, and therefore it cannot be said to be a desirable solution.